Chlorothalonil

Endpoint summary

Description of key information

- Skin irritation: not irritating, male, New-Zealand White rabbit, OECD 404, Johnson 2000

- Eye irritation: corrosive, male/female, New-Zealand White rabbit, no guideline, Major 1977

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 Dec 1999 to 16 Jan 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1992

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Version / remarks:

1992

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Version / remarks:

1998

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: Young adults
- Weight at study initiation: 2519 to 2976 g
- Housing: The rabbits were housed individually in cages suitable for animals of this strain and the weight range expected during the course of the study
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 ± 3
- Humidity (%): 30 to 70
- Air changes (per hr): A minimum of 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 20 Dec 1999, To: 16 Jan 2000

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

water

Remarks:

(deionised)

Controls:

no

Amount / concentration applied:

VEHICLE
- Amount applied: 0.5 to 0.6 mL

Duration of treatment / exposure:

4 hours

Observation period:

10 days

Number of animals:

3 males

Details on study design:

DOSE ADMINISTRATION
On the day prior to application of the test substance, the hair was removed with a pair of veterinary clippers from an area approximately 7 cm x 13 cm on the left flank of each animal. The test substance (approximately 500 mg) was moistened to a dry paste with a small amount (0.5 - 0.6 mL) of deionised water to allow good skin contact and, using a metal spatula, was applied to the test site (approximate size 2.5 cm x 2.5 cm) on the left flank of each rabbit. The treated area was covered with a piece of 4-ply surgical gauze (approximate size 2.5 cm x 2.5 cm), which was secured by two strips of surgical tape (approximate size 1 cm x 8 cm). This was covered by a piece of impermeable rubber sheeting (approximate size 35 cm x 13 cm) wrapped once around the trunk of the animal and secured with adhesive impermeable polyethylene tape.
The dressings were left in position for approximately four hours. After this time each dressing was carefully cut (using blunt-tipped scissors), removed and discarded. The application site was gently cleansed free of any residual test substance using clean swabs of absorbent cotton wool soaked in clean warm water and was then dried gently with clean tissue paper. The application site was identified using a black waterproof marker-pen.

CLINICAL OBSERVATIONS
Prior to the start of the study, all rabbits were examined to ensure that they were physically normal and exhibited normal activity. Throughout the study, the animals were observed daily for general signs of well-being. All animals were removed from the study at the end of the observation period.

IRRITATION RESPONSE
The Draize scale (see "Any other information on materials and methods incl. tables) was used to assess the degree of erythema and oedema at the application sites approximately 1 hour and 1, 2 and 3 days after removal of the dressings and then at intervals for up to 10 days. Any other signs of skin irritation were also noted.

BODY WEIGHTS
The body weight of each animal was recorded at the start of the study.

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 10 days

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 4 days

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 4 days

Irritant / corrosive response data:

Very slight erythema was seen in two animals for 1 hour or 5 days, and very slight to moderate/severe erythema was seen in one animal for 7 days. Very slight oedema was seen in one animal for 2 days and very slight to slight oedema was seen in another animal for 3 days. Additional signs of irritation comprised desquamation, thickening, scabbing and wrinkling. All signs of irritation had completely resolved 10 days after application.

Other effects:

There were no signs of ill-health in any animal during the study.

Table 1. Individual and mean skin irritation scores according to the Draize scheme

Time	Erythema			Oedema
Animal number	#1	#2	#3	#1	#2	#3
after 1 hour	1	1	2	0	0	1
after 24 hours	0	1	2	0	1	2
after 48 hours	0	1t	3tw	0	1	2
after 72 hours	0	1t	2ts	0	0	1
mean score 24-72 h	0	1.0	2.3	0	0.7	1.7
after 4 days	-	1dt	2ts	-	0	0
after 5 days	-	1d	2dts	-	0	0
after 7 days	-	0d	1dt	-	0	0
after 10 days	-	0	0	-	0	0

- Animal removed from study, d desquamation, t thickening, s scabbing, w wrinkling

 

Interpretation of results:

GHS criteria not met

Conclusions:

Based on this study the test substance is considered to be a mild irritant following a single four-hour application to rabbit skin, however not sufficient for classification under CLP.

Executive summary:

The skin irritation potential of the test substance was determined in vivo according to the OECD 404 test guideline and GLP principles. A group of 3 male rabbits received a single four-hour application of 500 mg test substance to the shorn flank. The animals were assessed for up to 10 days for any signs of skin irritation.

Very slight erythema was seen in two animals for 1 hour or 5 days, and very slight to moderate/severe erythema was seen in one animal for 7 days. Very slight oedema was seen in one animal for 2 days and very slight to slight oedema was seen in another animal for 3 days. Additional signs of irritation comprised desquamation, thickening, scabbing and wrinkling. All signs of irritation had completely resolved 10 days after application.

In conclusion, the test substance is considered to be a mild irritant following a single four-hour application to rabbit skin, however not sufficient for classification under CLP.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

9 Sep 1977 to 16 Oct 1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

A dose of 0.1 mg of test substance was instilled into one eye of each of three male and three female New Zealand White rabbits. The eyes were examined and scored at 24, 48, and 72 hours, and on days 7 and 14 according to a modified Draize system. A sodium fluorescein dye examination was conducted at 72 hours and on days 7 and 14 in order to detect potential corneal lesions.

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Age at study initiation: Not reported
- Weight at study initiation: 2002 to 2215 g
- Housing: The rabbits were individually housed in metal metabolism cages in temperature and humidity controlled quarters.
- Diet: Ad libitum
- Water: Ad libitum

IN-LIFE DATES: From: 9 Sep 1977 To: 16 Oct 1977

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 100 mg

Duration of treatment / exposure:

Single treatment

Observation period (in vivo):

24, 48, and 72 hours, and on days 7 and 14

Number of animals or in vitro replicates:

3 males and 3 females

Details on study design:

A dose of 0.1 mg of test substance was instilled into one eye of each of three male and three female New Zealand White rabbits. The left eye served as the untreated control for each rabbit. None of the rabbits received a washout. The eyes were examined and scored at 24, 48, and 72 hours, and on days 7 and 14 according to a modified Draize system. A sodium fluorescein dye examination was conducted at 72 hours and on days 7 and 14 in order to detect potential corneal lesions.

Irritation parameter:

cornea opacity score

Basis:

animal: 1, 2, 3, 4, 6

Time point:

24/48/72 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: Marked chemosis precluded observations for corneal and iridal irritation. Maximum score used due to marked chemosis which precluded a definitive score.

Irritation parameter:

cornea opacity score

Basis:

animal #5

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

iris score

Basis:

animal: 1, 2, 3, 4, 6

Time point:

24/48/72 h

Score:

2

Max. score:

2

Reversibility:

not fully reversible within: 14 days (7 days for animal 3 and 4)

Remarks on result:

other: Marked chemosis precluded observations for corneal and iridal irritation. Maximum score used due to marked chemosis which precluded a definitive score.

Irritation parameter:

iris score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0.7

Max. score:

2

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal: 1, 2, 4

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.8

Max. score:

3

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

animal: 5, 6

Time point:

24/48/72 h

Score:

1.5

Max. score:

3

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

chemosis score

Basis:

animal: 1, 2, 3, 5, 6

Time point:

24/48/72 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Irritation parameter:

chemosis score

Basis:

animal #4

Time point:

24/48/72 h

Score:

3.7

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Irritant / corrosive response data:

The test substance elicited ocular irritation in all six rabbits. Corneal opacities were observed in all eyes at all observation intervals with the exception of five out of six corneas at 24 hours and four out of six corneas at 48 hours which could not be observed due to severe chemosis. Pannus was observed in two out of six eyes at day 7. Vascularization of the corneal surface was noted in five out of six eyes at day 14. Peeling of the corneal epithelium was observed in all rabbits. Dendritic vascularization was noted in two out of six eyes at day 7. The sodium fluorescein dye examination confirmed the occurrence of corneal damage in all rabbits at all observation intervals.

Iritis (iris still reacting to light) was observed in all six eyes. The iris of five eyes at 24 hours, four eyes at 48 hours and one eye at 72 hours could not be observed due to severe chemosis. Iritis was observed in four out of six eyes on day 14.

Conjunctival irritation (redness, chemosis, discharge and blanching) was observed in all rabbits at all observation intervals. Petite conjunctival haemorrhages were observed in all rabbits through day 7 and persisted to day 14 in one rabbit eye.

The maximum mean total Draize score was 99.9 observed at 24 hours. The maximum individual total Draize score was 108.0 observed in three rabbits at 24 hours.

Table 1. results for individual animals

Scores observed after	24 hours	48 hours	72 hours		7 days	14 days
Cornea/opacity	*,2,*,*,*,*	* ,*, 3,*,*,*	2,4,2,3,4,3½		4,4,4,4,4,4	3,4,4,4,4,4
Iris	*,0,*,*,*,*	*,0,1,*,*,*	2,2,1,*,1,*		2,2,1,2,1,2	0,2,1,2,0,2
Conjunctiva redness	2,2,2,2,2,2	1½,1½,1,2,2,2	2,1,1½,2,2,2		1½,1,2,2½,2,2	½,1,1,1½,1,1
Conjunctiva chemosis	4,4,4,4,4,4	4,4,4,4,4,4	4,4,4,4,3,4	1½,4,1½,4,1½,4			1½,2,1½,1½,1½,2
Conjunctiva discharge	3,3,3,2,3,2	3,2,1½,1,1½,2	3,2,2,2,1,2	2,2,2,2,1,2			0,1,2,1,1,1

* Marked chemosis precluded these observations

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

A dose of 0.1 mg test substance produced corneal opacities, pannus, vascularization of the corneal surface, peeling of the corneal epithelium, dendritic vascularization, iritis, conjunctival irritation and petite conjunctival haemorrhages when instilled into the eyes of albino rabbits, Corneal opacity persisted through day 14 in all six rabbits tested.

Executive summary:

The eye irritation produced by a single application of the test material was assessed in a primary eye irritation study in New Zealand White rabbits (no guideline, GLP). A dose of 0.1 mg of test substance was instilled into one eye of each of three male and three female New Zealand White rabbits. The left eye served as the untreated control for each rabbit. None of the rabbits received a washout. The eyes were examined and scored at 24, 48, and 72 hours, and on days 7 and 14 according to a modified Draize system. A sodium fluorescein dye examination was conducted at 72 hours and on days 7 and 14 in order to detect potential corneal lesions. The test substance elicited ocular irritation in all six rabbits. Corneal opacities were observed in all eyes at all observation intervals with the exception of five out of six corneas at 24 hours and four out of six corneas at 48 hours which could not be observed due to severe chemosis. Pannus was observed in two out of six eyes at day 7. Vascularization of the corneal surface was noted in five out of six eyes at day 14. Peeling of the corneal epithelium was observed in all rabbits. Dendritic vascularization was noted in two out of six eyes at day 7. The sodium fluorescein dye examination confirmed the occurrence of corneal damage in all rabbits at all observation intervals. Iritis (iris still reacting to light) was observed in all six eyes. The iris of five eyes at 24 hours, four eyes at 48 hours and one eye at 72 hours could not be observed due to severe chemosis. Iritis was observed in four out of six eyes on day 14. Conjunctival irritation (redness, chemosis, discharge and blanching) was observed in all rabbits at all observation intervals. Petite conjunctival haemorrhages were observed in all rabbits through day 7 and persisted to day 14 in one rabbit eye.

In conclusion, the test substance produced corneal opacities, pannus, vascularization of the corneal surface, peeling of the corneal epithelium, dendritic vascularization, iritis, conjunctival irritation and petite conjunctival haemorrhages when instilled into the eyes of albino rabbits, Corneal opacity persisted through day 14 in all six rabbits tested.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin irritation

The skin irritation potential of the test substance was determined in vivo according to the OECD 404 test guideline and GLP principles. A group of 3 male rabbits received a single four-hour application of 500 mg test substance to the shorn flank. The animals were assessed for up to 10 days for any signs of skin irritation.

Very slight erythema was seen in two animals for 1 hour or 5 days, and very slight to moderate/severe erythema was seen in one animal for 7 days. Very slight oedema was seen in one animal for 2 days and very slight to slight oedema was seen in another animal for 3 days. Additional signs of irritation comprised desquamation, thickening, scabbing and wrinkling. All signs of irritation had completely resolved 10 days after application.

In conclusion, the test substance is considered to be a mild irritant following a single four-hour application to rabbit skin, however not sufficient for classification under CLP.

Eye irritation/corrosion

The eye irritation produced by a single application of the test material was assessed in a primary eye irritation study in New Zealand White rabbits (no guideline, GLP). A dose of 0.1 mg of test substance was instilled into one eye of each of three male and three female New Zealand White rabbits. The left eye served as the untreated control for each rabbit. None of the rabbits received a washout. The eyes were examined and scored at 24, 48, and 72 hours, and on days 7 and 14 according to a modified Draize system. A sodium fluorescein dye examination was conducted at 72 hours and on days 7 and 14 in order to detect potential corneal lesions. The test substance elicited ocular irritation in all six rabbits. Corneal opacities were observed in all eyes at all observation intervals with the exception of five out of six corneas at 24 hours and four out of six corneas at 48 hours which could not be observed due to severe chemosis. Pannus was observed in two out of six eyes at day 7. Vascularization of the corneal surface was noted in five out of six eyes at day 14. Peeling of the corneal epithelium was observed in all rabbits. Dendritic vascularization was noted in two out of six eyes at day 7. The sodium fluorescein dye examination confirmed the occurrence of corneal damage in all rabbits at all observation intervals. Iritis (iris still reacting to light) was observed in all six eyes. The iris of five eyes at 24 hours, four eyes at 48 hours and one eye at 72 hours could not be observed due to severe chemosis. Iritis was observed in four out of six eyes on day 14. Conjunctival irritation (redness, chemosis, discharge and blanching) was observed in all rabbits at all observation intervals. Petite conjunctival haemorrhages were observed in all rabbits through day 7 and persisted to day 14 in one rabbit eye.

In conclusion, the test substance produced corneal opacities, pannus, vascularization of the corneal surface, peeling of the corneal epithelium, dendritic vascularization, iritis, conjunctival irritation and petite conjunctival haemorrhages when instilled into the eyes of albino rabbits, Corneal opacity persisted through day 14 in all six rabbits tested.

Respiratory irritation

In an acute inhalation toxicity study the test substance was administered at concentrations of 0.08, 0.14, 0.21 mg/L and dose related mortalities occurred at all dose levels tested. There was evidence of respiratory tract irritancy, at all dose levels including macroscopic pathology in decedents. Clinical signs observed at all concentrations of the test substance during the 4-hour exposure period, were consistent with inhalation of an irritant aerosol, including partial closing of eyes, wetness around the eyes, exaggerated respiratory movements and restless behaviour. Gasping was observed in rats exposed at 0.14 or 0.21 mg/L. Clinical signs following exposure included exaggerated respiratory movements and discharge from the eyes. Deaths as a result of exposure occurred on days 0-2. Recovery from the effects of exposure was evident from day 4 and the majority of surviving rats had recovered by day 9. Typically, the rats that died showed congestion of the lungs. There were no macroscopic abnormalities in rats that survived until scheduled termination.

Justification for classification or non-classification

Based on the available information, classification for skin is not warranted in accordance with EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation No. (EC) 1272/2008.

Based on the available information, the test substance is classified for Eye damage category 1, H318: causes serious eye damage in accordance with EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation No. (EC) 1272/2008.

Based on the available information, the test substance is classified for STOT-SE Cat. 3, H335: May cause respiratory irritation in accordance with EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation No. (EC) 1272/2008.